Camera module including liquid lens, and control method thereof

ABSTRACT

A camera module includes a liquid lens including a first plate and an individual electrode disposed on a first surface of the first plate; a resistor disposed on the first surface of the first plate so as to be spaced apart from the individual electrode; and a temperature sensor connected to the resistor and configured to sense a temperature of the liquid lens and a heating controller connected to the resistor and configured to control a temperature of the liquid lens.

TECHNICAL FIELD

Embodiments relate to a camera module including a liquid lens and acontrol method thereof.

BACKGROUND ART

People who use portable devices demand optical devices that have highresolution, are small, and have various photographing functions. Forexample, these various photographing functions may be at least one of anoptical zoom-in/zoom-out function, an auto-focusing (AF) function, or ahand-tremor compensation or optical image stabilization (OIS) function.

In the conventional art, in order to implement the various photographingfunctions described above, a method of combining a plurality of lensesand directly moving the combined lenses is used. In the case in whichthe number of lenses is increased, however, the size of the opticaldevice may increase.

The auto-focusing and hand-tremor compensation functions are performedby moving or tilting a plurality of lenses, which are secured to a lensholder and are aligned along an optical axis, in an optical-axisdirection or a direction perpendicular to the optical axis. To this end,a separate lens-moving apparatus is required in order to move a lensassembly composed of a plurality of lenses. However, the lens-movingapparatus has high power consumption, and an additional cover glassneeds to be provided separately from a camera module in order to protectthe lens-moving apparatus, thus causing a problem in that the overallsize of the conventional camera module is increased. In order to solvethis, studies have been conducted on a liquid lens that performsauto-focusing and hand-tremor compensation functions by electricallyadjusting the curvature and tilting of an interface between two types ofliquids.

DISCLOSURE Technical Problem

Embodiments provide a camera module including a liquid lens that iscapable of controlling the temperature of the liquid lens and a controlmethod thereof.

The objects to be accomplished by the embodiments are not limited to theabove-mentioned objects, and other objects not mentioned herein will beclearly understood by those skilled in the art from the followingdescription.

Technical Solution

A camera module according to an embodiment may include a liquid lensincluding a first plate and an individual electrode disposed on a firstsurface of the first plate, a resistor disposed on the first surface ofthe first plate so as to be spaced apart from the individual electrode,a temperature sensor connected to the resistor and configured to sensethe temperature of the liquid lens, and a heating controller connectedto the resistor and configured to control the temperature of the liquidlens.

For example, the temperature sensor may include a sensing driverconfigured to supply a sensing signal to one end of the resistor, andthe heating controller may include a heating driver configured to supplya heating signal to the one end of the resistor.

For example, the camera module may include a first switch disposedbetween the resistor and the sensing driver, a second switch disposedbetween the resistor and the heating driver, and a switch controllerconfigured to control the first and second switches.

For example, the resistor may include an opposite end connected to areference potential.

For example, the camera module may include a connection substrateconnected to the individual electrode and the resistor, and the resistormay include first and second resistors, which are disposed so as to faceeach other, with the center of the liquid lens interposed therebetween.

For example, the temperature sensor may be connected to one end of thesecond resistor via one end of the first resistor and the opposite endof the first resistor.

For example, the heating controller may be connected to the one end ofthe first resistor and the one end of the second resistor.

For example, the opposite end of the first resistor may be connected tothe reference potential, and the camera module may include a thirdswitch, disposed between the opposite end of the first resistor and thereference potential, and a fourth switch, disposed between the oppositeend of the first resistor and the one end of the second resistor.

According to another embodiment, a control method of a camera module mayinclude sensing the temperature of the liquid lens, detecting adifference between the sensed temperature and a set target temperatureof the liquid lens, and applying power to the resistor when there is adifference between the sensed temperature and the set target temperatureof the liquid lens.

For example, the control method of the camera module may includemaintaining a current state when there is no difference between thesensed temperature and the set target temperature of the liquid lens.

Advantageous Effects

According to a camera module including a liquid lens and a controlmethod thereof according to the embodiments, a member corresponding to athermistor and a member corresponding to a heater are disposed on asurface on which individual electrodes are disposed in the liquid lens,rather than being disposed on a surface on which a common electrode isdisposed, whereby influence on the common electrode, which is areference electrode, may be prevented, and thus operational stabilitymay be secured.

In addition, in the case of a camera module according to theembodiments, since a resistor, which serves as a thermistor or a heater,is disposed on a first surface of a first plate, which is wider than asecond surface of the first plate in the liquid lens, it is notnecessary to increase the overall size of the liquid lens, making itpossible to easily reduce the size of a bezel or eliminate a bezel.

In addition, in the case of a camera module according to theembodiments, since a resistor, which serves as a thermistor, is disposedon a first surface of a first plate, which is wider than a secondsurface of the first plate, the resistor is capable of being formed overa larger area than when the same is disposed on the second surface,whereby it is possible to more accurately sense the temperature of aliquid lens.

In addition, in the case of a camera module according to theembodiments, since a resistor is capable of serving both as a thermistorand as a heater, utilization of space inside the camera module isimproved.

However, the effects achievable through the embodiments are not limitedto the above-mentioned effects, and other effects not mentioned hereinwill be clearly understood by those skilled in the art from thefollowing description.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic block diagram of a camera module according to anembodiment.

FIG. 2 is a perspective view of embodiments of the liquid lens and theresistor shown in FIG. 1.

FIG. 3 is a cross-sectional view taken along line I-I′ in FIG. 2.

FIG. 4 shows an equivalent circuit of the liquid lens shown in FIG. 2.

FIG. 5 is a view for explaining the planar shape of an embodiment of theresistor shown in FIG. 1.

FIG. 6 is a view for explaining the planar shape of another embodimentof the resistor shown in FIG. 1.

FIG. 7 is a perspective view of a liquid lens module according to anembodiment.

FIG. 8 is a diagram for explaining the operation of an embodiment of thecamera module shown in FIG. 1.

FIG. 9 shows an equivalent circuit of the camera module shown in FIG. 8when a driving signal is supplied in the form of current.

FIG. 10 shows an equivalent circuit of the camera module shown in FIG. 8when a driving signal is supplied in the form of voltage.

FIG. 11 is a diagram for explaining the operation of another embodimentof the camera module shown in FIG. 1.

FIG. 12 is a flowchart for explaining a control method of the cameramodule according to an embodiment.

FIG. 13 is an exploded perspective view of an embodiment of the cameramodule shown in FIG. 1.

FIG. 14 is a view for explaining the holder and the liquid lens moduleshown in FIG. 13.

FIGS. 15(a) and (b) are partial plan views of a camera module accordingto a comparative example.

BEST MODE

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

The technical spirit of the disclosure is not limited to the embodimentsto be described, and may be implemented in various other forms, and oneor more of the components may be selectively combined and substitutedfor use without exceeding the scope of the technical spirit of thedisclosure.

In addition, terms (including technical and scientific terms) used inthe embodiments of the disclosure, unless specifically defined anddescribed explicitly, are to be interpreted as having meanings that maybe generally understood by those having ordinary skill in the art towhich the disclosure pertains, and meanings of terms that are commonlyused, such as terms defined in a dictionary, should be interpreted inconsideration of the context of the relevant technology.

Further, the terms used in the embodiments of the disclosure are forexplaining the embodiments and are not intended to limit the disclosure.In this specification, the singular forms may also include plural formsunless otherwise specifically stated in a phrase, and in the case inwhich “at least one (or one or more) of A, B, or C” is stated, it mayinclude one or more of all possible combinations of A, B, and C.

In addition, in describing the components of the embodiments of thedisclosure, terms such as “first”, “second”, “A”, “B”, “(a)”, and “(b)”can be used. Such terms are only for distinguishing one component fromanother component, and do not determine the nature, sequence orprocedure etc. of the corresponding constituent elements.

In addition, when it is described that a component is “connected”,“coupled” or “joined” to another component, the description may includenot only being directly “connected”, “coupled” or “joined” to the othercomponent but also being “connected”, “coupled” or “joined” by anothercomponent between the component and the other component.

In addition, in the case of being described as being formed or disposed“above (on)” or “below (under)” another component, the descriptionincludes not only the case where the two components are in directcontact with each other, but also the case where one or more othercomponents are formed or disposed between the two components. Inaddition, when expressed as “above (on)” or “below (under)”, it mayrefer to a downward direction as well as an upward direction withrespect to one element.

A variable lens may be a variable focus lens. Further, a variable lensmay be a lens that is adjustable in focus. A variable lens may be atleast one of a liquid lens, a polymer lens, a liquid crystal lens, a VCMtype, or an SMA type. A liquid lens may include a liquid lens includingone liquid and a liquid lens including two liquids. A liquid lensincluding one liquid may change the focus by adjusting a membranedisposed at a position corresponding to the liquid, for example, bypressing the membrane using the electromagnetic force between a magnetand a coil. A liquid lens including two liquids may include a conductiveliquid and a non-conductive liquid, and may adjust the interface formedbetween the conductive liquid and the non-conductive liquid usingvoltage applied to the liquid lens. A polymer lens may change the focusby controlling a polymer material using a driver such as a piezoactuator. A liquid crystal lens may change the focus by controlling aliquid crystal using electromagnetic force. A VCM type may change thefocus by adjusting a solid lens or a lens assembly including a solidlens using electromagnetic force between a magnet and a coil. An SMAtype may change the focus by controlling a solid lens or a lens assemblyincluding a solid lens using a shape memory alloy.

Hereinafter, camera modules 1000 and 1000A according to embodiments willbe described as including a liquid lens as a variable lens, but theembodiments are not limited thereto.

Hereinafter, camera modules 1000 and 1000A including a liquid lensaccording to embodiments will be described with reference to theaccompanying drawings. Although the camera modules 1000 and 1000A willbe described using the Cartesian coordinate system (x-axis, y-axis,z-axis) for convenience of description, they may also be described usingany of other coordinate systems. Although the x-axis, the y-axis, andthe z-axis of the Cartesian coordinate system are perpendicular to eachother, the embodiments are not limited thereto. That is, the x-axis, they-axis, and the z-axis may intersect each other obliquely.

FIG. 1 is a schematic block diagram of a camera module 1000 according toan embodiment. Here, LX represents an optical axis.

The camera module 1000 shown in FIG. 1 may include a liquid lens 110, aresistor 120, a temperature sensor 210, and a heating controller 220.

Although it is illustrated in FIG. 1 that the resistor 120 belongs to alens assembly 100, the embodiments are not limited thereto. That is,unlike what is shown in FIG. 1, the resistor 120 may be a constituentelement of the camera module 1000, rather than being a constituentelement of the lens assembly 100. Further, the embodiments are notlimited to any specific configuration of the lens assembly 100 in whichthe liquid lens 110 is included. An example of the lens assembly 100will be described later with reference to FIG. 13.

FIG. 2 is a perspective view of embodiments 110A and 120A of the liquidlens 110 and the resistor 120 shown in FIG. 1.

FIG. 3 is a cross-sectional view taken along line I-I′ in FIG. 2.

The liquid lens 110A and the resistor 120A shown in FIGS. 2 and 3, whichwill be described below, are merely given as examples for helpingunderstand the liquid lens 110 and the resistor 120 shown in FIG. 1.That is, the liquid lens 110 and the resistor 120 shown in FIG. 1 mayhave various shapes different from those shown in FIGS. 2 and 3.

The liquid lens 110A shown in FIGS. 2 and 3 may include a plurality ofdifferent types of liquids LQ1 and LQ2, first to third plates P1, P2 andP3, first and second electrodes E1 and E2, and an insulation layer 116.

The liquid lens 110A may include a cavity CA. The plurality of liquidsLQ1 and LQ2 may be accommodated in the cavity CA, and may include afirst liquid LQ1, which is conductive, and a second liquid (or aninsulative liquid) LQ2, which is non-conductive. The first liquid LQ1and the second liquid LQ2 may be immiscible with each other, and aninterface BO may be formed at a contact portion between the first andsecond liquids LQ1 and LQ2. In an example, the second liquid LQ2 may bedisposed on the first liquid LQ1, but the embodiments are not limitedthereto.

In addition, in the cross-sectional shape of the liquid lens 110A, theedges of the first and second liquids LQ2 and LQ1 may be thinner thanthe center portions thereof.

The first liquid LQ1 may be a conductive material, and the second liquidLQ2 may be an insulative material, which is non-conductive.

The inner side surface of the first plate P1 may form a sidewall i ofthe cavity CA. The first plate P1 may include upper and lower openingshaving a predetermined inclined surface. That is, the cavity CA may be athrough-hole area formed in the first plate P1.

As shown in FIG. 3, the area of the first opening in the direction inwhich light is introduced into the cavity CA may be smaller than thearea of the second opening in the opposite direction. Alternatively, theliquid lens 110A may be disposed such that the direction of inclinationof the cavity CA is opposite what is illustrated. That is, unlike theillustration of FIG. 3, the area of the second opening in the directionin which light is introduced into the cavity CA may be greater than thearea of the first opening in the opposite direction. In addition, whenthe liquid lens 110A is disposed such that the direction of inclinationof the cavity CA is opposite what is illustrated, the arrangement of allor some of the components included in the liquid lens 110A may bechanged, or only the direction of inclination of the cavity CA may bechanged and the arrangement of the remaining components may not bechanged, according to the direction of inclination of the liquid lens110A.

The diameter of the wider opening among the first and second openingsmay be set in consideration of the field of view (FOV) required for theliquid lens 110A or the role of the liquid lens 110A in the cameramodule 1000. According to the embodiment, the size (or the area or thewidth) of the second opening O₂ may be greater than the size (or thearea or the width) of the first opening O₁. Here, the size of each ofthe first and second openings may be the cross-sectional area in thehorizontal direction (e.g. the x-axis direction and the y-axisdirection). For example, the size of each of the first and secondopenings may mean the radius when the opening has a circularcross-section, and may mean the diagonal length when the opening has asquare cross-section.

Each of the first and second openings may take the form of a hole havinga circular cross-section. The interface BO formed by the two liquids maybe moved along the inclined surface of the cavity CA by a drivingvoltage.

The first liquid LQ1 and the second liquid LQ2 are charged,accommodated, or disposed in the cavity CA in the first plate P1. Inaddition, the cavity CA is a portion through which the light incident onthe liquid lens 110A passes. Thus, the first plate P1 may be formed of atransparent material, or may include impurities so that light does noteasily pass therethrough.

The multiple first electrodes E1 may be disposed so as to be spacedapart from the second electrode E2, and may be respectively disposed ona first surface SF1 (i.e. the upper surface), the side surface, and thelower surface of the first plate P1. The second electrode E2 may bedisposed on at least a portion of a second surface SF2 (i.e. the lowersurface) of the first plate P1, and may be in direct contact with thefirst liquid LQ1.

Referring to FIG. 3, if the area of the top of the first plate P1 andthe area of the bottom thereof are the same as each other before thefirst and second openings are formed, since the first opening has asmaller area than the second area as described above, the area of thefirst surface SF1 around the first opening in the first plate P1 islarger than the area of the second surface SF2 around the second openingin the first plate P1.

In addition, the first electrodes E1 may be “n” electrodes (hereinafterreferred to as “individual electrodes”), and the second electrode E2 maybe a single electrode (hereinafter referred to as a “common electrode”).Here, “n” is a positive integer of 2 or greater.

Hereinafter, the case in which n=4, i.e. in which the first electrodesE1 include four individual electrodes E11, E12, E13 and E14, will bedescribed, but the embodiments are not limited thereto.

A portion of the second electrode E2 disposed on the second surface SF2of the first plate P1 may be exposed to the first liquid LQ1, which isconductive.

Each of the first and second electrodes E1 and E2 may be formed of aconductive material, e.g. metal.

In addition, the second plate P2 may be disposed on one surface of eachof the first electrodes E1. That is, the second plate P2 may be disposedabove the first surface SF1 of the first plate P1. Specifically, thesecond plate P2 may be disposed on the upper surfaces of the firstelectrodes E1 and the cavity CA.

The third plate P3 may be disposed on one surface of the secondelectrode E2. That is, the third plate P3 may be disposed below thesecond surface SF2 of the first plate P1. Specifically, the third plateP3 may be disposed under the lower surface of the second electrode E2and the cavity CA.

The second plate P2 and the third plate P3 may be disposed so as to faceeach other, with the first plate P1 interposed therebetween. Inaddition, at least one of the second plate P2 or the third plate P3 maybe omitted.

At least one of the second plate P2 or the third plate P3 may have arectangular planar shape. The third plate P3 may be brought into contactwith and bonded to the first plate P1 on a bonding area around the edgethereof.

Each of the second and third plates P2 and P3 may be an area throughwhich light passes, and may be formed of a light-transmissive material.For example, each of the second and third plates P2 and P3 may be formedof glass, and, for convenience of processing, may be formed of the samematerial.

The second plate P2 may be configured to allow the light incident on theliquid lens 110A to travel into the cavity CA in the first plate P1.

The third plate P3 may be configured to allow the light that has passedthrough the cavity CA in the first plate P1 to be emitted from theliquid lens 110A. The third plate P3 may be in direct contact with thefirst liquid LQ1.

According to the embodiment, the third plate P3 may have a diametergreater than the diameter of the wider opening among the first andsecond openings in the first plate P1. In addition, the third plate P3may include a peripheral area spaced apart from the first plate P1.

The insulation layer 116 may be disposed so as to cover a portion of thelower surface of the second plate P2 in the upper area of the cavity CA.That is, the insulation layer 116 may be disposed between the secondliquid LQ2 and the second plate P2.

In addition, the insulation layer 116 may be disposed so as to coverportions of the first electrodes E1 that form the sidewall of the cavityCA. In addition, the insulation layer 116 may be disposed on the lowersurface of the first plate P1 so as to cover portions of the firstelectrodes E1, a portion of the first plate P1, and a portion of thesecond electrode E2. Thus, contact between the first electrode E1 andthe first liquid LQ1 and contact between the first electrode E1 and thesecond liquid LQ2 may be prevented by the insulation layer 116. Theinsulation layer 116 may cover one electrode among the first and secondelectrodes E1 and E2 (e.g. the first electrodes E1), and may expose aportion of the other electrode (e.g. the second electrode E2) so thatelectrical energy is applied to the first liquid LQ1, which isconductive.

FIG. 4 shows an equivalent circuit of the liquid lens 110A shown in FIG.2.

The operation of the liquid lens 110A will be described below withreference to FIGS. 2 and 4.

The liquid lens 110A, the interface BO of which is adjusted in shape inresponse to a driving voltage, may receive the driving voltage viamultiple first electrodes E1: E11, E12, E13 and E14, which are disposedin four different directions at the same angular interval, and thesecond electrode E2: CO. When the driving voltage is applied via any oneof the multiple first electrodes E1: E11, E12, E13 and E14 and thesecond electrode E2: CO, the shape of the interface BO between the firstliquid LQ1 and the second liquid LQ2, which are disposed in the cavityCA, may be deformed. The degree of deformation and the shape of theinterface BO between the first liquid LQ1 and the second liquid LQ2 maybe controlled by the control circuit 200 in order to implement at leastone of the AF function or the OIS function. That is, the control circuit200 may generate a driving voltage to control the liquid lens 110A.

In addition, referring to FIG. 4, the liquid lens 110A may beconceptually explained as a plurality of capacitors CAP, in which oneside of the liquid lens 110A receives voltages from the first electrodesE1: E11, E12, E13 and E14 and the other side of the liquid lens 110A isconnected to the second electrode E2: CO to receive a voltage therefrom.

Meanwhile, in order to explain the concept of the camera module 1000according to the embodiment, the resistor 120 is illustrated in FIG. 1as being spaced apart from the liquid lens 110. However, the resistor120 may be disposed inside the liquid lens 110. That is, according tothe embodiment, the resistor 120 shown in FIG. 1 may be spaced apartfrom the first electrodes E1: E11, E12, E13 and E14, which areindividual electrodes, as shown in FIG. 2, and may be disposed on thefirst surface SF1 of the first plate P1, on which the first electrodesE1: E11, E12, E13 and E14, which are individual electrodes, aredisposed, as shown in FIG. 3. Alternatively, the resistor may bedisposed on the first surface SF1, which is the wider surface among thefirst surface SF1 and the second surface SF2 of the first plate P1.

FIGS. 5 and 6 are views for explaining the planar shapes of variousembodiments 120A and 120B of the resistor 120 shown in FIG. 1.

FIG. 3 corresponds to a cross-sectional view taken along line I-I′ inFIG. 5. The resistor 120 shown in each of FIGS. 3, 5 and 6 is embeddedin the second plate P2, as shown in FIG. 3, and thus is not visible.However, for better understanding, the resistors 120A and 120B are shownin FIGS. 3, 5 and 6.

According to an embodiment, the resistor 120 shown in FIG. 1 may includefirst and second resistors 120A1 and 120A2, which are spaced apart fromeach other and are disposed on the same surface of the first plate P1,i.e. the first surface SF1, as shown in FIGS. 2 and 5.

In addition, as shown in FIG. 5, the first resistor 120A1 and the secondresistor 120A2 may have planar shapes, which are symmetric to each otherwith respect to a surface that is perpendicular to the y-axis direction,is parallel to the x-axis and the z-axis, and passes through the centerof the liquid lens 110A, but the embodiments are not limited thereto.

In addition, the first and second resistors 120A1 and 120A2 may bedisposed so as to face each other, with the center of the liquid lens110A interposed therebetween.

According to another embodiment, the resistor 120 shown in FIG. 1 mayinclude a single resistor 120B, as shown in FIG. 6. In addition, asshown in FIG. 6, the resistor 120B may have a planar shape, which issymmetric with respect to a surface that is perpendicular to the y-axisdirection, is parallel to the x-axis and the z-axis, and passes throughthe center of the liquid lens 110A, but the embodiments are not limitedthereto.

FIGS. 2, 5 and 6 show exemplary planar shapes of the resistors 120A and120B, but the embodiments are not limited thereto, and may providevarious other planar shapes thereof.

Hereinafter, the resistors 120A and 120B shown in FIGS. 5 and 6 will bedescribed in detail.

As shown in FIG. 3, the resistor 120A may be disposed between the firstsurface SF1 of the first plate P1 and the second plate P2. Therefore,although the resistor 120A is not visible from the outside, the same isindicated by the dotted lines in FIG. 2 in order to promote anunderstanding of the embodiment. Further, although not shown, theresistor 120B shown in FIG. 6 may also be disposed so as to be embeddedin the second plate P2, like the resistor 120A.

Further, referring to FIG. 3, the first and second resistors 120A1 and120A2 may be disposed on the first plate P1.

For better understanding, insulation layers IS1 and IS2, which are notvisible from the outside, are illustrated in FIG. 5. Although theinsulation layers IS1 and IS2 are illustrated in FIG. 5 as beingdisposed around the first and second resistors 120A1 and 120A2, theembodiments are not limited to any specific planar shape of theinsulation layers IS1 and IS2. Further, although not shown, theinsulation layers IS1 and IS2 may also have planar shapes forelectrically separating the four first electrodes E11, E12, E13 and E14from each other.

Current may be supplied to the resistors 120A and 120B in order to sensethe temperature of the liquid lens 110A or to heat the liquid lens 110A,which will be described later with reference to FIGS. 8 and 11. In thiscase, when the resistors 120A and 120B are directly disposed on thefirst electrodes E1 without interposing the insulation layers IS1 andIS2 between the resistors 120A and 120B and the first electrodes E1, thefirst electrodes E1 and the resistors 120A and 120B may beshort-circuited. In order to prevent this, the insulation layers IS1 andIS2 are disposed between the first electrodes E1 and the resistors 120Aand 120B in order to electrically separate these components E1, 120A and120B from each other, thereby preventing these components E1, 120A and120B from being short-circuited. An air layer, a glass layer, which isgenerated due to fusion of the first plate and the second plate, oranother insulation member may be disposed as the insulation layers IS1and IS2, or the insulation layers IS1 and IS2 may be formed of the samematerial as that of the insulation layer 116 shown in FIG. 3.

For example, when receiving a sensing signal from the temperature sensor210, the resistors 120A and 120B may sense the temperature of the liquidlens 110A, and when receiving a heating signal from the heatingcontroller 220, the resistors 120A and 120B may be implemented asresistors capable of heating the liquid lens 110A. That is, whenreceiving a sensing signal from the temperature sensor 210, theresistors 120A and 120B may serve as a thermistor. A thermistor is asemiconductor that is sensitive to heat and has a resistance value thatchanges with changes in temperature. Alternatively, when receiving aheating signal from the heating controller 220, the resistors 120A and120B may serve as heating resistors that generate heat when currentflows therethrough.

The embodiments are not limited to any specific type of resistors 120Aand 120B. That is, any element can be employed as the resistors 120A and120B, so long as it is capable of generating heat when receiving acurrent and the characteristic value (e.g. a resistance value) thereofchanges with changes in the temperature of the liquid lens 110A.

Meanwhile, referring again to FIG. 1, the temperature sensor 210 may beconnected to the resistor 120 to sense information on the temperature ofthe liquid lens 110 (or the temperature of the resistor 120), and mayoutput the sensed temperature information through an output terminalOUT. The temperature sensor 210 may be included in the control circuit200, but the embodiments are not limited to any specific configurationof the control circuit 200 in which the temperature sensor 210 isincluded. For example, the temperature sensor 210 may be disposed on aconnection substrate, which electrically connects the control circuit200 to the liquid lens.

In addition, the heating controller 220 may be connected to the resistor120 to control the heating operation of the resistor 120. In addition,the heating controller 220 may control the amount of heat emitted fromthe resistor 120 as well as the heating operation of the resistor 120.

The control circuit 200, which is capable of performing the functions ofthe temperature sensor 210 and the heating controller 220, may serve tosupply a driving voltage (or an operation voltage) to the liquid lens110. The control circuit 200 and the image sensor 300 may be mounted ona single main board, for example, a printed circuit board (PCB), butthis is merely given by way of example, and the embodiments are notlimited thereto. That is, the temperature sensor 210 and the heatingcontroller 220 may be disposed on the main board. The control circuit200 may correspond to the main board 480 shown in FIG. 13, to bedescribed later.

The image sensor 300 may perform a function of converting the light thathas passed through the liquid lens 110 of the lens assembly 100 intoimage data. More specifically, the image sensor 300 may generate imagedata by converting light into analog signals via a pixel array includinga plurality of pixels and synthesizing digital signals corresponding tothe analog signals.

When the camera module 1000 according to the embodiment is applied to anoptical device (or an optical instrument), the configuration of thecontrol circuit 200 may be designed in different ways depending on thespecifications of the optical device. In particular, the control circuit200 may be implemented as a single chip so as to reduce the magnitude ofthe driving voltage that is applied to the lens assembly 100. Thereby,the size of an optical device mounted in a portable device may befurther reduced.

The liquid lens 110: 110A and the resistor 120: 120A and 120B shown inFIGS. 1 to 3, 5 and 6 may be modularized.

Hereinafter, the modularized liquid lens 110 or 110A will be referred toas a “liquid lens module”, and a liquid lens module 130 will bedescribed below with reference to FIG. 7. Hereinafter, the liquid lensmodule 130 will be described as including the resistor 120A shown inFIG. 5, but the following description may also apply to the case inwhich the liquid lens module 130 includes the resistor 120B shown inFIG. 6, unless otherwise noted. That is, the resistor 120A shown in FIG.7 may be replaced with the resistor 120B shown in FIG. 6. That is, theliquid lens module 130 may include the resistor 120B shown in FIG. 6,rather than the resistor 120A shown in FIG. 5.

FIG. 7 is a perspective view of the liquid lens module 130 according toan embodiment.

Although the resistor 120A is embedded in the liquid lens 110A, the sameis illustrated in FIG. 7 as being located outside the liquid lens 110Ain order to help understand the connection relationships between a firstconnection substrate 132 and the resistor 120A.

FIG. 7 is a plan view showing the state before a first connectionsubstrate 132 and a second connection substrate 134 are bent in the−z-axis direction.

The liquid lens module 130 may include a first connection substrate 132,a liquid lens 110A, a resistor 120A, and a second connection substrate134. The liquid lens 110A and the resistor 120 according to theembodiment are not limited to any specific configuration of the liquidlens module 130 to be described below.

Since the liquid lens 110A and the resistor 120A shown in FIG. 7respectively correspond to the liquid lens 110A and the resistor 120Ashown in FIGS. 2, 3 and 5, the same reference numerals are used, and aduplicate description thereof is omitted.

The first connection substrate 132 may electrically connect the multiplefirst electrodes E1: E11, E12, E13 and E14 included in the liquid lens110A to the main board including the control circuit 200, and may bedisposed on the liquid lens 110A. In addition, the first connectionsubstrate 132 may electrically connect the resistor 120A to the mainboard.

The first connection substrate 132 and the resistor 120A may beelectrically connected to each other in any of various forms. An examplethereof will be described below with reference to FIGS. 2, 3 and 5 to 7,but the embodiments are not limited thereto.

Referring to FIGS. 2, 3 and 5 to 7, in order to allow the firstelectrodes E1: E11, E12, E13 and E14 to be electrically connected to thefirst connection substrate 132, the second plate P2 exposes portions ofthe first electrodes E1. Similarly, the second plate P2 may expose endportions of the resistor 120: 120A and 120B.

For example, referring to FIGS. 2, 5 and 6, in order to electricallyconnect the four first electrodes E1: E11, E12, E13 and E14 to the firstconnection substrate 132, the second plate P2 may include therein firstto fourth recesses H1 to H4. The first recess H1 exposes one E11 of thefirst electrodes E1, the second recess H2 exposes another one E12 of thefirst electrodes E1, the third recess H3 exposes still another one E13of the first electrodes E1, and the fourth recess H4 exposes stillanother one H14 of the first electrodes E1.

In addition, in the case in which the resistor 120 shown in FIG. 1 isimplemented as shown in FIG. 5, the second plate P2 of the liquid lens110A shown in FIG. 2 may further include therein fifth to eighthrecesses H5 to H8. Referring to FIGS. 2 and 5, the fifth recess H1exposes one end T11 of the first resistor 120A1, the sixth recess H6exposes the opposite end T12 of the first resistor 120A1, the seventhrecess H7 exposes one end T21 of the second resistor 120A2, and theeighth recess H8 exposes the opposite end T22 of the second resistor120A2.

FIG. 2 shows the state after the first to eighth recesses H1 to H8 areformed in the second plate P2, and FIG. 5 shows the state before thefirst to eighth recesses H1 to H8 are formed in the second plate P2.

Alternatively, in the case in which the resistor 120 shown in FIG. 1 isimplemented as shown in FIG. 6, the second plate P2 of the liquid lens110A shown in FIG. 2 may include therein first to fourth, ninth andtenth recesses H1 to H4, H9 and H10. Referring to FIG. 6, the ninthrecess H9 exposes one end T31 of the resistor 120B, and the tenth recessH10 exposes the opposite end T32 of the resistor 120B. FIG. 6 shows thestate before the first to fourth, ninth and tenth recesses H1 to H4, H9and H10 are formed in the second plate P2.

Referring to FIGS. 5 and 6, in the liquid lens 110A, the first surfaceSF1 of the first plate P1 may include first and second edge areas EA1and EA2. The first edge area EA1 may be an area that faces the secondedge area EA2, with the center of the liquid lens 110A interposedtherebetween. That is, the second edge area EA2 may be an area that isopposite the first edge area EA1.

Referring to FIG. 5, one end T11 and the opposite end T12 of the firstresistor 120A1 and some E11 and E14 of the first electrodes E1 may bedisposed in the first edge area EA1, and one end T21 and the oppositeend T22 of the second resistor 120A2 and some E12 and E13 of the firstelectrodes E1 may be disposed in the second edge area EA2.

Referring again to FIG. 7, the first connection substrate 132 mayinclude first protruding portions P11 to P14, which protrude from therespective four inner corners thereof toward the liquid lens 110A andare respectively electrically or physically connected to the four firstelectrodes E11, E12, E13 and E14, which are respectively exposed throughthe first to fourth recesses H1 to H4. Among the first protrudingportions, the 1-1^(st) protruding portion P11 may be electrically orphysically connected to the 1-1^(st) electrode E11, which is exposedthrough the first recess H1, the 1-2^(nd) protruding portion P12 may beelectrically or physically connected to the 1-2^(nd) electrode E12,which is exposed through the second recess H2, the 1-3^(rd) protrudingportion P13 may be electrically or physically connected to the 1-3^(rd)electrode E13, which is exposed through the third recess H3, and the1-4^(th) protruding portion P14 may be electrically or physicallyconnected to the 1-4^(th) electrode E14, which is exposed through thefourth recess H4.

In addition, the first connection substrate 132 may include secondprotruding portions P21 to P24, which protrude from the inner edgesurfaces between the inner corners thereof toward the liquid lens 110A.Among the second protruding portions, the 2-1^(st) protruding portionP21 is electrically or physically connected to one end T11 of the firstresistor 120A1, which is exposed through the fifth recess H5. The2-2^(nd) protruding portion P22 is electrically or physically connectedto the opposite end T12 of the first resistor 120A1, which is exposedthrough the sixth recess H6. The 2-3^(rd) protruding portion P23 iselectrically or physically connected to one end T21 of the secondresistor 120A2, which is exposed through the seventh recess H7. The2-4^(th) protruding portion P24 may be electrically or physicallyconnected to the opposite end T22 of the second resistor 120A2, which isexposed through the eighth recess H8.

However, in the case in which the resistor 120 is implemented as shownin FIG. 6, although not shown, the first connection substrate 132 mayinclude third protruding portions P31 and P32. Among the thirdprotruding portions, the 3-1^(st) protruding portion P31 may beelectrically connected to one end T31 of the resistor 120B, which isexposed through the ninth recess H9, and the 3-2^(nd) protruding portionP32 may be electrically connected to the opposite end T32 of theresistor 120B, which is exposed through the tenth recess H10.

Referring to FIG. 7, the first connection substrate 132 may include aconnection pad CP1, which is electrically connected to the four firstprotruding portions PT11 to P14 and the four second protruding portionsP21 to P24. The connection pad CP1 of the first connection substrate 132may be electrically connected to an electrode pad (not shown), which isformed on the main board (e.g. 480 shown in FIG. 13) of the controlcircuit 200. To this end, after the first connection substrate 132 isbent in the −z-axis direction toward the main board, the connection padCP1 and the electrode pad may be electrically connected to each othervia conductive epoxy.

If the first connection substrate 132 further includes the four secondprotruding portions P25 to P28 described above, the connection pad CP1may be electrically connected to the four second protruding portions P25to P28. In addition, if the first connection substrate 132 furtherincludes the two third protruding portions P31 and P32 described above,the connection pad CP1 may be electrically connected to the two thirdprotruding portions P31 and P32.

In addition, the first connection substrate 132 may be implemented as aflexible printed circuit board (FPCB).

The second connection substrate 134 may electrically connect the secondelectrode E2 included in the liquid lens 110A to the main board (e.g.480 shown in FIG. 13), and may be disposed below the liquid lens 110A.The second connection substrate 134 may be implemented as an FPCB or asingle metal substrate (a conductive metal plate).

The second connection substrate 134 may be electrically connected to theelectrode pad, which is formed on the main board, via a connection padCP2, which is electrically connected to the second electrode E2. To thisend, the second connection substrate 134 may be bent in the −z-axisdirection toward the main board 200.

The liquid lens module 130 according to the embodiment may furtherinclude a spacer 136.

The spacer 136 may have a ring shape, and may be disposed between thefirst connection substrate 132 and the second connection substrate 134so as to surround the side surface of the liquid lens 110A, therebyprotecting the liquid lens 110A from external impacts. To this end, thespacer 136 may have a shape that allows the liquid lens 110A to bemounted in, seated in, in contact with, fixed to, provisionally fixedto, supported by, coupled to, or disposed in the spacer.

Hereinafter, an example in which the temperature sensor 210 shown inFIG. 1 senses the temperature of the liquid lens 110 using the resistor120 or the heating controller 220 heats the liquid lens 110 using theresistor 120 will be described with reference to the accompanyingdrawings.

First, an embodiment in which the resistor 120A shown in FIG. 5 is usedto sense the temperature of the liquid lens 110A or to heat the liquidlens 110A will be described below with reference to FIGS. 8 to 10.

FIG. 8 is a diagram for explaining the operation of an embodiment of thecamera module 1000 shown in FIG. 1.

The temperature sensor 210A and the heating controller 220A shown inFIG. 8 respectively correspond to embodiments of the temperature sensor210 and the heating controller 220 shown in FIG. 1.

The electrical connection relationships in the case in which the firstand second resistors 120A1 and 120A2 are used in order to sense thetemperature of the liquid lens 110A will be described below.

The temperature sensor 210A may be connected to one end T11 of the firstresistor 120A1. To this end, one end T11 of the first resistor 120A1 maybe electrically connected to the temperature sensor 210A, which isdisposed on the main board (e.g. 480 shown in FIG. 13), via the firstconnection substrate 132. Alternatively, as will be described later, thetemperature sensor 210A may be connected to the opposite end T22 of thesecond resistor 120A2 as well as one end T11 of the first resistor120A1. To this end, one end T11 of the first resistor 120A1 and theopposite end T22 of the second resistor 120A2 may be electricallyconnected to the temperature sensor 210A, which is disposed on the mainboard, via the first connection substrate 132.

In addition, the opposite end T12 of the first resistor 120A1 may beconnected to one end T21 of the second resistor 120A2. To this end, theopposite end T12 of the first resistor 120A1 may be connected to one endT21 of the second resistor 120A2 via the first connection substrate 132or via the first connection substrate 132 and the main board.Accordingly, the temperature sensor 210A may be connected to one end T21of the second resistor 120A2 via one end T11 and the opposite end T12 ofthe first resistor 120A1.

The opposite end T22 of the second resistor 120A2 may be connected to areference potential (or ground) or a resistor R2. To this end, theopposite end T22 of the second resistor 120A2 may be connected to thereference potential or the resistor R2 via the first connectionsubstrate 132 or via the first connection substrate 132 and the mainboard.

The electrical connection relationships in the case in which the firstand second resistors 120A1 and 120A2 are used in order to heat theliquid lens 110A will be described below.

In order to control the generation of heat by the resistor 120, theheating controller 220 shown in FIG. 1 serves to supply a heating signalto one end of the resistor 120. In the embodiment, when the resistor 120shown in FIG. 1 includes the first and second resistors 120A1 and 120A2,as shown in FIGS. 5 and 8, the heating controller 220A may be configuredas a first heating driver 220A, which is one heating driver, or mayinclude first and second heating drivers 220A1 and 220A2.

The first heating driver 220A1 may supply a first heating signal to oneend T11 of the first resistor 120A1, and the second heating driver 220A2may supply a second heating signal to one end T21 of the second resistor120A2. To this end, the first heating driver 220A1 may be connected toone end T11 of the first resistor 120A1, and the second heating driver220A2 may be connected to one end T21 of the second resistor 120A2. Forexample, one end T11 of the first resistor 120A1 and one end T21 of thesecond resistor 120A2 may be respectively electrically connected to thefirst and second heating drivers 220A1 and 220A2, which are disposed onthe main board (e.g. 480 shown in FIG. 13), via the first connectionsubstrate 132.

In addition, the opposite ends T12 and T22 of the first and secondresistors 120A1 and 120A2 may be connected to the reference potential(e.g. ground). To this end, the opposite ends T12 and T22 of the firstand second resistors 120A1 and 120A2 may be connected to the referencepotential via the first connection substrate 132 and the main board.

According to the embodiment, the temperature sensor 210A may include asensing driver 212 and a temperature information measurer 214.

The sensing driver 212 serves to supply a driving signal (or a sensingsignal) to the first and second resistors 120A. For example, the sensingdriver 212 may supply a driving signal to the first and second resistors120A through one end T11 of the first resistor 120A1. The driving signalsupplied from the sensing driver 212 may be a current type or a voltagetype.

According to an embodiment, when the sensing driver 212 supplies acurrent-type driving signal, the sensing driver 212 may include acurrent source IS in FIG. 8.

According to another embodiment, when the sensing driver 212 supplies avoltage-type driving signal, the sensing driver 212 may include a supplyvoltage VDS and a first resistor R1 in FIG. 8. The first resistor (orload resistor) R1 may be connected between the supply voltage VDS andone end T11 of the first resistor 120A1.

According to still another embodiment, when the sensing driver 212selectively supplies a current-type driving signal or a voltage-typedriving signal, the sensing driver 212 may include first and secondswitches S1 and S2 in addition to the current source IS, the supplyvoltage VDS, and the first resistor R1, and the camera module 1000 mayfurther include third to sixth switches S3 to S6 and a resistor R2.Turn-on and turn-off operations of the first to sixth switches S1 to S6may be controlled by the main board of the control circuit 200 shown inFIG. 1. To this end, the control circuit 200A may further include aseparate switch controller 230. The switch controller 230 may generateand output switch control signals for turning on or off the first tosixth switches S1 to S6.

The first switch S1 may be disposed between the constant current sourceIS and one end T11 of the first resistor 120A1, and the second switch S2may be disposed between the resistor R1 and one end T11 of the firstresistor 120A1.

The third switch S3 may be disposed between the temperature informationmeasurer 214 and one end T11 of the first resistor 120A1, and the fourthswitch S4 may be disposed between the temperature information measurer214 and the opposite end T22 of the second resistor 120A2.

The fifth switch S5 may be disposed between the opposite end T22 of thesecond resistor 120A2 and the reference potential (or ground), and thesixth switch S6 may be disposed between the opposite end T22 of thesecond resistor 120A2 and the resistor R2. The seventh switch S7 may bedisposed between the opposite end T12 of the first resistor 120A1 andone end T21 of the second resistor 120A2. The second resistor R2 may bedisposed between the sixth switch S6 and the reference potential.

The temperature information measurer 214 may be connected to theresistor 120A to measure the temperature information of the resistor120S.

When the sensing driver 212 supplies a current-type driving signal, thetemperature information measurer 214 may be connected to one end T11 ofthe first resistor 120A1 to measure temperature information of the firstand second resistors 120A1 and 120A2.

Alternatively, when the sensing driver 212 supplies a voltage-typedriving signal, the temperature information measurer 214 may beconnected to the opposite end T22 of the second resistor 120A2 tomeasure temperature information of the first and second resistors 120A1and 120A2.

That is, the temperature information measurer 214 may measure thevoltage VS1 at one end T11 of the first resistor 120A1 or the voltageVS2 at the opposite end T22 of the second resistor 120A2, and maymeasure temperature information of the first and second resistors 120A1and 120A2 based on the measured voltage VS1 or VS2. To this end, thetemperature information measurer 214 may include an analog/digitalconverter 214A. The analog/digital converter 214A may measure thevoltage VS1 or VS2, may convert the measured voltage VS1 or VS2 into adigital form, and may output the result of the conversion as temperatureinformation of the resistor 120A through the output terminal OUT.

Hereinafter, the operation of measuring temperature information of thefirst and second resistors 120A1 and 120A2 by the temperature sensor210A will be described.

FIG. 9 shows an equivalent circuit of the camera module shown in FIG. 8when a driving signal is supplied in the form of current.

First, the operation of the temperature information measurer 214 whenthe sensing driver 212 supplies a driving signal in the form of currentwill be described below with reference to FIGS. 8 and 9.

The first, third, fifth and seventh switches S1, S3, S5 and S7 areturned on, and all of the remaining switches, i.e. the second, fourthand sixth switches S2, S4 and S6 and the eighth to tenth switches S8 toS10, are turned off. Accordingly, the camera module shown in FIG. 8 mayrealize electric connection as shown in FIG. 9.

The eighth switch S8 may be disposed between a resistor R3 and one endT11 of the first resistor 120A1, the ninth switch S9 may be disposedbetween a resistor R4 and one end T21 of the second resistor 120A2, andthe tenth switch S10 may be disposed between the opposite end T12 of thefirst resistor 120A1 and the reference potential. In addition, theresistor R3 may be disposed between a supply voltage VDH1 and the eighthswitch S8, and the resistor R4 may be disposed between a supply voltageVDH2 and the ninth switch S9.

Referring to FIG. 9, the current I output from the constant currentsource IS flows in the direction of the arrow. In this case, the voltageVS1 sensed by the temperature information measurer 214 is expressedusing Equation 1 below.

VS1=I×RT  [Equation 1]

Here, RT represents the resistance value obtained by summing theresistance value RT1 of the first resistor 120A1 and the resistancevalue RT2 of the second resistor 120A2.

The sensed voltage VS1 in Equation 1 is converted into a digital form bythe analog/digital converter 214A, and is output as the temperatureinformation of the first and second resistors 120A1 and 120A2 throughthe output terminal OUT.

The temperatures of the first and second resistors 120A1 and 120A2 maybe estimated using the temperature information output through the outputterminal OUT. That is, in Equation 1, since the current I is a constantfixed value supplied from the constant current source IS, RT can bedetermined using VS1. If the first and second resistors 120A1 and 120A2serve as negative thermistors having resistance values RT1 and RT2 thatare inversely proportional to temperature, the resistance value RTdecreases as the temperature increases. On the other hand, if the firstand second resistors 120A1 and 120A2 serve as positive thermistorshaving resistance values RT1 and RT2 that are proportional totemperature, the resistance value RT increases as the temperatureincreases. In this way, the digital-type voltage VS1 output from thetemperature sensor 214 through the output terminal OUT may be convertedinto the temperature of the resistor 120A.

FIG. 10 shows an equivalent circuit of the camera module shown in FIG. 8when a driving signal is supplied in the form of voltage.

First, the operation of the temperature information measurer 214 whenthe sensing driver 212 supplies a driving signal in the form of voltagewill be described below with reference to FIGS. 8 and 10.

The second, fourth, sixth and seventh switches S2, S4, S6 and S7 areturned on, and the first, third and fifth switches S1, S3 and S5 and theeighth to tenth switches S8 to S10 are turned off. Accordingly, thecamera module shown in FIG. 8 may realize electric connection as shownin FIG. 10.

Referring to FIG. 10, when a voltage-type driving signal is applied fromthe supply voltage VDS through the resistor R1, the voltage VS2 at theopposite end T22 of the second resistor 120A2 sensed by the temperatureinformation measurer 214 is expressed using Equation 2 below.

$\begin{matrix}{{{VS}\; 2} = {{VDS} \cdot \frac{R\; 2}{{RT} + {R\; 2}}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

Here, RT represents the resistance value obtained by summing theresistance value RT1 of the first resistor 120A1 and the resistancevalue RT2 of the second resistor 120A2 as described above, VDSrepresents the supply voltage, which is a fixed value, and R2 representsthe external resistor, which has a fixed resistance value. In Equation2, the value of the first resistor R1 is a negligible value, and thus isomitted. However, if the value of the first resistor R1 is applied,Equation 2 may be expressed as Equation 3 below.

$\begin{matrix}{{{VS}\; 2} = {{VDS} \cdot \frac{R\; 2}{{RT} + {R\; 2} + {R\; 1}}}} & \left\lbrack {{Equation}\mspace{14mu} 3} \right\rbrack\end{matrix}$

The sensed voltage VS2 may be converted into a digital form by theanalog/digital converter 214A, and may be output as the temperatureinformation of the resistor 120A through the output terminal OUT.

The temperature of the resistor 120A can be determined using thetemperature information output through the output terminal OUT. That is,in Equation 2, since the supply voltage VDS and the value of the secondresistor R2 are fixed values, RT can be determined using VS2.Alternatively, in Equation 3, since the supply voltage VDS and thevalues of the first and second resistors R1 and R2 are fixed values, RTcan be determined using VS2. If the first and second resistors 120A1 and120A2 serve as negative thermistors having resistance values RT1 and RT2that are inversely proportional to temperature, the resistance value RTdecreases as the temperature increases. On the other hand, if the firstand second resistors 120A1 and 120A2 serve as positive thermistorshaving resistance values RT1 and RT2 that are proportional totemperature, the resistance value RT increases as the temperatureincreases. In this way, the digital-type voltage VS2 output from thetemperature sensor 214 through the output terminal OUT may be convertedinto the temperature of the resistor 120A.

Hereinafter, an operation of heating the liquid lens 110A using thefirst and second resistors 120A1 and 120A2 by the heating controller220A will be described.

When the heating controller 220A intends to heat the liquid lens 110Ausing at least one of the first or second resistor 120A1 or 120A2, thefirst to fourth, sixth and seventh switches S1 to S4, S6 and S7associated with sensing of temperature may be turned off.

In order to allow the first resistor 120A1 to generate heat, the firstheating driver 220A1 may include a supply voltage VDH1, a resistor R3,and an eighth switch S8, and the camera module 1000 may further includea tenth switch S10. The resistor R3 may be disposed between the supplyvoltage VDH1 and the eighth switch S8. When the eighth switch S8 isturned on, the resistor R3 may be connected between the supply voltageVDH1 and one end T11 of the first resistor 120A1.

When the eighth and tenth switches S8 and S10 are turned on, a firstheating signal is supplied from the first heating driver 220A1 to thefirst resistor 120A1, whereby the first resistor 120A1 may generateheat.

In order to allow the second resistor 120A2 to generate heat, the secondheating driver 220A2 may include a supply voltage VDH2, a resistor R4,and a ninth switch S9. The resistor R4 may be disposed between thesupply voltage VDH2 and the ninth switch S9. When the ninth switch S9 isturned on, the resistor R4 may be connected between the supply voltageVDH2 and one end T21 of the second resistor 120A2.

When the fifth and ninth switches S5 and S9 are turned on, a secondheating signal is supplied from the second heating driver 220A2 to thesecond resistor 120A2, whereby the second resistor 120A2 may generateheat.

In addition, in FIG. 8, when the fifth and eighth to tenth switches S5and S8 to S10 are simultaneously turned on, the first and secondresistors 120A1 and 120A2 may generate heat at the same time.

As described above, in order to allow the first and second resistors120A1 and 120A2 to selectively perform the operation of sensing thetemperature of the liquid lens 110A and the operation of heating theliquid lens 110A, the switch controller 230 may generate and outputswitch control signals for turning on or off the first to tenth switchesS1 to S10.

In FIG. 8, it is possible to sense the temperature of the liquid lens110A using the first to eighth switches S1 to S7 and to heat the liquidlens 110A using the fifth and eighth to tenth switches S5 and S8 to S10.

The switch controller 230 may turn on/off the switches S1 to S10 forrespective operations as shown in Table 1 below.

TABLE 1 Classification OP1 OP2 OP3 OP4 OP5 S1 1 0 0 0 0 S2 0 1 0 0 0 S31 0 0 0 0 S4 0 1 0 0 0 S5 1 0 0 1 1 S6 0 1 0 0 0 S7 1 1 0 0 0 S8 0 0 1 01 S9 0 0 0 1 1 S10 0 0 1 0 1

In Table 1, OP1 represents the switching operation of sensing thetemperature of the liquid lens 110A when a current-type driving signalis applied thereto, OP2 represents the switching operation of sensingthe temperature of the liquid lens 110A when a voltage-type drivingsignal is applied thereto, OP3 represents the switching operation ofcontrolling only the first resistor 120A1 to generate heat, OP4represents the switching operation of controlling only the secondresistor 120A2 to generate heat, and OP5 represents the switchingoperation of controlling the first and second resistors 120A1 and 120A2to simultaneously generate heat. In Table 1, “0” represents that acorresponding switch is in a turned-off state, and “1” represents that acorresponding switch is in a turned-on state.

Meanwhile, an embodiment in which the resistor 120B shown in FIG. 6 isused to sense the temperature of the liquid lens 110A or to heat theliquid lens 110A will be described below with reference to FIG. 11.

FIG. 11 is a diagram for explaining the operation of another embodimentof the camera module 1000 shown in FIG. 1.

Unlike the illustration of FIG. 8, the camera module 1000 shown in FIG.11 includes only one resistor 120B. Except for this, the camera module1000 shown in FIG. 11 is the same as the camera module 1000 shown inFIG. 8. Thus, only parts different from those of FIG. 8 will bedescribed with reference to FIG. 11, and a description of the same partsis omitted. That is, the temperature sensor 210A and the heating driver220A1 shown in FIG. 11 respectively correspond to the temperature sensor210A and the first heating driver 220A1 shown in FIG. 8.

Referring to FIG. 11, the first switch S1 may be disposed between theconstant current source IS and one end T31 of the resistor 120B, and thesecond switch S2 may be disposed between the resistor R1 and one end T31of the resistor 120B.

The third switch S3 may be disposed between the temperature informationmeasurer 214 and one end T31 of the resistor 120B, and the fourth switchS4 may be disposed between the temperature information measurer 214 andthe opposite end T32 of the resistor 120B.

The fifth switch S5 may be disposed between the opposite end T32 of theresistor 120B and the reference potential (or ground), and the sixthswitch S6 may be disposed between the opposite end T32 of the resistor120B and the resistor R2. The resistor R2 may be disposed between thesixth switch S6 and the reference potential.

The eighth switch S8 may be disposed between the resistor R3 and one endT31 of the resistor 120B.

The electrical connection relationships in the case in which theresistor 120B is used in order to sense the temperature of the liquidlens 110A will be described below.

The temperature sensor 210A may be connected to one end T31 of theresistor 120B. To this end, one end T31 of the resistor 120B may beelectrically connected to the temperature sensor 210A disposed on themain board (e.g. 480 shown in FIG. 13) via the first connectionsubstrate 132. Alternatively, as will be described later, thetemperature sensor 210A may also be connected to the opposite end T32 aswell as one end T31 of the resistor 120B. To this end, one end T31 andthe opposite end T32 of the resistor 120B may be electrically connectedto the temperature sensor 210A disposed on the main board via the firstconnection substrate 132.

When the fifth switch S5 is turned on, the opposite end T32 of theresistor 120B may be connected to the reference potential (or ground),and when the sixth switch S6 is turned on, the opposite end T32 of theresistor 120B may be connected to the resistor R2. In this case, theopposite end T32 of the resistor 120B may be connected to the referencepotential or the resistor R2 via the first connection substrate 132 andthe main board.

The electrical connection relationships in the case in which theresistor 120B is used in order to heat the liquid lens 110A will bedescribed below.

In order to control the generation of heat by the resistor 120, theheating controller 220 shown in FIG. 1 serves to supply a heating signalto one end of the resistor 120. In the embodiment, when the resistor 120shown in FIG. 1 includes the resistor 120B, as shown in FIGS. 6 and 11,the heating controller 220A may include only one first heating driver220A1.

The first heating driver 220A1 may supply a first heating signal to oneend T31 of the resistor 120B. To this end, when the eighth switch S8 isturned on, the first heating driver 220A1 may be connected to one endT31 of the resistor 120B, and when the fifth switch S5 is turned on, theopposite end T32 of the resistor 120B may be connected to the referencepotential. For example, one end T31 of the resistor 120B may beconnected to the first heating driver 220A1 of the main board via thefirst connection substrate 132, and the opposite end T32 thereof may beconnected to the reference potential via the first connection substrate132 and the main board.

According to the embodiment, the temperature sensor 210A may include asensing driver 212 and a temperature information measurer 214, like theillustration of FIG. 8.

The sensing driver 212 serves to supply a driving signal (or a sensingsignal) to the resistor 120B. For example, the sensing driver 212 maysupply a driving signal to the resistor 120B through one end T31 of theresistor 120B.

When the sensing driver 212 supplies a current-type driving signal, thetemperature information measurer 214 may be connected to one end T31 ofthe resistor 120B, and may measure temperature information of theresistor 120B.

Alternatively, when the sensing driver 212 supplies a voltage-typedriving signal, the temperature information measurer 214 may beconnected to the opposite end T32 of the resistor 120B, and may measuretemperature information of the resistor 120B.

That is, the temperature information measurer 214 may measure thevoltage VS1 at one end T31 of the resistor 120B or the voltage VS2 atthe opposite end T32 of the resistor 120B, and may measure temperatureinformation of the resistor 120B based on the measured voltage VS1 orVS2.

Since the switching operations of the first to sixth switches formeasurement of temperature information of the resistor 120B by thetemperature sensor 210A shown in FIG. 11 are the same as described withreference to FIG. 8, a duplicate description thereof is omitted.

In addition, when the first heating driver 220A1 shown in FIG. 11intends to allow the resistor 120B to generate heat, the fifth andeighth switches S5 and S8 may be turned on, and the first to fourth andsixth switches S1 to S4 and S6 may be turned off. Accordingly, a firstheating signal may be supplied from the first heating driver 220A1 tothe resistor 120B, whereby the resistor 120B may generate heat.

Similar to the illustration of FIG. 8, in the camera module shown inFIG. 11, in order to allow the resistor 120B to selectively perform theoperation of sensing the temperature of the liquid lens 110A and theoperation of heating the liquid lens 110A, the switch controller 230 maygenerate and output switch control signals for turning on or off thefirst to sixth and eighth switches S1 to S6 and S8.

In FIG. 11, it is possible to sense the temperature of the liquid lens110A using the first to sixth switches S1 to S6 and to heat the liquidlens 110A using the fifth and eighth switches S5 and S8.

The switch controller 230 shown in FIG. 11 may turn on/off the switchesS1 to S6 and S8 for respective operations as shown in Table 2 below.

TABLE 2 Classification OP1 OP2 OP3 S1 1 0 0 S2 0 1 0 S3 1 0 0 S4 0 1 0S5 1 0 1 S6 0 1 0 S8 0 0 1

In Table 2, OP1 represents the switching operation of sensing thetemperature of the liquid lens 110A when a current-type driving signalis applied thereto, OP2 represents the switching operation of sensingthe temperature of the liquid lens 110A when a voltage-type drivingsignal is applied thereto, and OP3 represents the switching operation ofcontrolling the resistor 120B to generate heat. In Table 2, “0”represents that a corresponding switch is in a turned-off state, and “1”represents that a corresponding switch is in a turned-on state.

Hereinafter, a control method of the above-described camera module 1000will be described with reference to FIGS. 1, 8, 11 and 12.

FIG. 12 is a flowchart for explaining a control method 500 of the cameramodule 1000 according to an embodiment.

Referring to FIG. 12, the temperature of the liquid lens 110A is sensedfirst (step 510). Step 510 may be performed by the temperature sensor210 or 210A.

Referring to FIG. 8, in order to sense the temperature of the liquidlens 110A, the switching controller 230 turns on the seventh switch S7,turns off the eighth to tenth switches S8 to S10, and controls theswitching operations of the first to sixth switches S1 to S6 such thatthe temperature sensor 210A measures temperature information of theresistor 120A (refer to OP1 and OP2 described in Table 1 above).

Alternatively, referring to FIG. 11, in order to sense the temperatureof the liquid lens 110A, the switching controller 230 turns off theeighth switch S8, and controls the switching operations of the first tosixth switches S1 to S6 such that the temperature sensor 210A measurestemperature information of the resistor 120B (refer to OP1 and OP2described in Table 2 above).

After step 510, a difference between the sensed temperature and the settarget temperature of the liquid lens 110A is detected (step 520). Step520 may be performed by the control circuit 200. For example, step 520may be performed by the switch controller 230.

When there is a difference between the sensed temperature and the settarget temperature of the liquid lens 110A, power is applied to theresistor 120A or 120B (step 530).

Referring to FIG. 8, when the temperature difference is large, theswitching controller 230 may generate switch control signals such thatthe fifth, eighth, ninth and tenth switches S5, S8, S9 and S10 in FIG. 8are simultaneously turned on (refer to OP5 described in Table 1 above).Accordingly, the heating controller 220A may control the first andsecond resistors 120A1 and 120A2 to simultaneously generate heat,thereby heating the liquid lens 110A within a short time.

However, when the temperature difference is not large, the switchingcontroller 230 may turn on the eighth and tenth switches S8 and S10, ormay turn on the fifth and ninth switches S5 and S9 (refer to OP3 or OP4described in Table 1 above). Accordingly, the heating controller 220Amay perform control such that any one of the first and second resistors120A1 and 120A2 generates heat to heat the liquid lens 110A.

Also, when there is no difference between the sensed temperature and theset target temperature of the liquid lens 110A, the current state ismaintained (step 540). To this end, the switching controller 230 maygenerate switch control signals such that the fifth and eighth to tenthswitches S5 and S8 to S10 shown in FIG. 8 are turned off. Accordingly,neither of the first and second resistors 120A1 and 120A2 generatesheat.

Hereinafter, an embodiment of the camera module 1000 according to theabove-described embodiment will be described with reference to FIGS. 13and 14.

FIG. 13 is an exploded perspective view of an embodiment 1000A of thecamera module 1000 shown in FIG. 1.

Referring to FIG. 13, the camera module 1000A may include a lensassembly, an image sensor 300, and a main board 480. Here, the lensassembly, the image sensor 300, and the main board 480 respectivelycorrespond to embodiments of the lens assembly, the image sensor 300,and the control circuit 200 shown in FIG. 1.

In addition, the camera module 1000A may further include a first cover410 and a middle base 450. In addition, the camera module 1000A mayfurther include a sensor base 460 and a filter 470. In addition, thecamera module 1000A may further include a circuit cover 472. The circuitcover 472 may have an electromagnetic shielding function.

According to the embodiment, at least one of the components 420 to 470of the camera module 1000A shown in FIG. 13 may be omitted.Alternatively, at least one component different from the components 420to 470 shown in FIG. 13 may be further included in the camera module1000A.

Referring to FIG. 13, the lens assembly may include at least one of aliquid lens module 130, a first lens unit 420, a holder 430, or a secondlens unit 440, and may be disposed on a main board 480. One of the firstlens unit 420 and the second lens unit 440 of the lens assembly may beomitted.

In the lens assembly, the first lens unit 420 and the second lens unit440 may be respectively referred to as a “first solid lens unit” and a“second solid lens unit” in order to be distinguished from the liquidlens 110A.

The first lens unit 420 may be disposed at the upper side of the lensassembly, and may be a region on which light is incident from outsidethe lens assembly. That is, the first lens unit 420 may be disposedabove the liquid lens module 130 within the holder 430. The first lensunit 420 may be implemented using a single lens, or may be implementedusing two or more lenses that are aligned along a center axis to form anoptical system. Here, the center axis may be the optical axis LX of theoptical system, which is formed by the first lens unit 420, the liquidlens module 130, and the second lens unit 440 included in the cameramodule 1000A, or may be an axis parallel to the optical axis LX. Theoptical axis LX may correspond to the optical axis of the image sensor300. That is, the first lens unit 420, the liquid lens module 130, thesecond lens unit 440, and the image sensor 300 may be aligned along theoptical axis LX through active alignment (AA). Here, “active alignment”may mean an operation of aligning the optical axes of the first lensunit 420, the second lens unit 440, and the liquid lens module 130 witheach other and adjusting the axial or distance relationships between theimage sensor 300, the lens units 420 and 440, and the liquid lens module130 in order to acquire an improved image.

FIG. 14 is a view for explaining the holder 430 and the liquid lensmodule 130 shown in FIG. 13. That is, FIG. 14 is an exploded perspectiveview of the holder 430 and the liquid lens unit 130. The holder 430shown in FIG. 14 may include first and second holes HO1 and H02 andfirst to fourth sidewalls.

The first and second holes HO1 and H02 may be respectively formed in theupper portion and the lower portion of the holder 430 to open the upperportion and the lower portion of the holder 430, respectively. Here, thefirst hole HO1 and the second hole H02 may be through-holes. The firstlens unit 420 may be accommodated in, mounted in, seated in, in contactwith, fixed to, provisionally fixed to, supported by, coupled to, ordisposed in the first hole HO1, which is formed in the holder 430, andthe second lens unit 440 may be accommodated in, mounted in, seated in,in contact with, fixed to, provisionally fixed to, supported by, coupledto, or disposed in the second hole H02, which is formed in the holder430.

In addition, the first and second sidewalls of the holder 430 may bedisposed so as to face each other in a direction perpendicular to thedirection of the optical axis LX (e.g. in the x-axis direction), and thethird and fourth sidewalls may be disposed so as to face each other in adirection perpendicular to the x-axis direction and to the direction ofthe optical axis LX (e.g. in the y-axis direction). In addition, asillustrated in FIG. 14, the first sidewall of the holder 430 may includea third opening OP3, and the second sidewall thereof may include afourth opening OP4, having a shape that is the same as or similar tothat of the third opening OP3. Thus, the third opening OP3 formed in thefirst sidewall and the fourth opening OP4 formed in the second sidewallmay be disposed so as to face each other in a direction perpendicular tothe direction of the optical axis LX (e.g. in the x-axis direction).

The inner space in the holder 430, in which the liquid lens module 130is disposed, may be open due to the third and fourth openings OP3 andOP4. In this case, the liquid lens module 130 may be inserted throughthe third or fourth opening OP3 or OP4 so as to be mounted in, seatedin, in contact with, fixed to, provisionally fixed to, supported by,coupled to, or disposed in the inner space in the holder 430. Forexample, the liquid lens module 130 may be inserted into the inner spacein the holder 430 through the third opening OP3.

As such, in order to allow the liquid lens module 130 to be insertedinto the inner space in the holder 430 through the third or fourthopening OP3 or OP4, the size of the third or fourth opening OP3 or OP4in the holder 430 in the direction of the optical axis LX may be greaterthan the cross-sectional area of the liquid lens module 130 in they-axis direction and the z-axis direction. For example, the height Hcorresponding to the size of each of the third and fourth openings OP3and OP4 in the direction of the optical axis LX may be greater than thethickness TO of the liquid lens module 130.

The second lens unit 440 may be disposed below the liquid lens module130 within the holder 430. The second lens unit 440 may be disposed soas to be spaced apart from the first lens unit 420 in the optical-axisdirection (e.g. in the z-axis direction).

The light introduced into the first lens unit 420 from outside thecamera module 1000A may pass through the liquid lens module 130 and maybe introduced into the second lens unit 440. The second lens unit 440may be implemented using a single lens, or may be implemented using twoor more lenses, which are aligned along the center axis to form anoptical system.

Unlike the liquid lens module 130, each of the first lens unit 420 andthe second lens unit 440 may be a solid lens formed of glass or plastic,but the embodiments are not limited to any specific material of each ofthe first lens unit 420 and the second lens unit 440.

Referring again to FIG. 13, the first cover 410 may be disposed so as tosurround the holder 430, the liquid lens module 130, and the middle base450, and may protect these components 430, 130 and 450 from externalimpacts. In particular, since the first cover 410 is disposed, aplurality of lenses, which form the optical system, may be protectedfrom external impacts.

In addition, in order to allow the first lens unit 420 disposed in theholder 430 to be exposed to external light, the first cover 410 mayinclude an upper opening 410H formed in the upper surface of the firstcover 410.

In addition, the first cover 410 may be disposed so as to cover theupper surface and the first to fourth sidewalls of the holder 430.

In addition, the middle base 450 may be disposed so as to surround thesecond hole H02 in the holder 430. To this end, the middle base 450 mayinclude an accommodating hole 450H for accommodating the second hole H02therein.

In the same manner as the upper opening 410H in the first cover 410, theaccommodating hole 450H may be formed near the center of the middle base450 at a position corresponding to the position of the image sensor 300,which is disposed in the camera module 1000A.

The middle base 450 may be mounted on the main board 480 so as to bespaced apart from a circuit element 481 on the main board 480. That is,the holder 430 may be disposed on the main board 480 so as to be spacedapart from the circuit element 481.

The main board 480 may be disposed below the middle base 450, and mayinclude a recess in which the image sensor 300 may be mounted, seated,tightly disposed, fixed, provisionally fixed, supported, coupled, oraccommodated, the circuit element 481, a connection part (or an FPCB)482, and a connector 483.

The circuit element 481 of the main board 480 may constitute a controlmodule, which controls the liquid lens module 130 and the image sensor300. The circuit element 481 may include at least one of a passiveelement and an active element, and may have any of various areas andheights. The circuit element 481 may be provided in a plural number, andmay have a height greater than the height of the main board 480 so as toprotrude outwards. The plurality of circuit elements 481 may be disposedso as not to overlap the holder 430 in the direction parallel to theoptical axis LX. For example, the plurality of circuit elements 481 mayinclude a power inductor, a gyro sensor, and the like, but theembodiments are not limited to any specific type of the circuit elements481.

In addition, the circuit elements 481 may calculate the temperature ofthe resistor 120A or 120B using the voltage values VS1 and VS2 outputthrough the output terminal OUT shown in FIG. 1, and may transmit thecalculated temperature to the outside through the connector 483. Inaddition, the circuit elements 481 may include the first to tenthswitches S1 to S10 shown in FIG. 8 or the first to sixth and eighthswitches S1 to S6 and S8 shown in FIG. 11, and may serve as the switchcontroller 230 controlling the on/off operation of the switches S1 toS10 or the switches S1 to S6 and S8.

The main board 480 may include a holder area in which the holder 430 isdisposed and an element area in which the plurality of circuit elements481 is disposed.

The main board 480 may be implemented as a rigid flexible printedcircuit board (RFPCB) including the FPCB 482. The FPCB 482 may be bentdepending on the requirement of the space in which the camera module1000A is mounted.

Meanwhile, the connector 483 may electrically connect the main board 480to a power supply or other devices (e.g. an application processor)outside the camera module 1000A.

Meanwhile, some of the plurality of circuit elements 481 shown in FIG.13 may cause electromagnetic interference (EMI) or noise. In particular,among the plurality of circuit elements 481, a power inductor 481-1 maycause greater EMI than other elements. In order to block EMI or noise,the circuit cover 472 may be disposed so as to cover the circuitelements 481 disposed in the element area of the main board 480.

In addition, when the circuit cover 472 is disposed so as to cover thecircuit elements 481, the circuit elements 481 disposed on the mainboard 480 may be protected from external impacts. To this end, thecircuit cover 472 may include an accommodating space for accommodatingtherein and covering the circuit elements 481, in consideration of theshape and position of the circuit elements 481 disposed on the mainboard 480.

Meanwhile, the filter 470 may filter light within a specific wavelengthrange, among the light that has passed through the first lens unit 420,the liquid lens module 130, and the second lens unit 440. The filter 470may be an infrared (IR) light blocking filter or an ultraviolet (UV)light blocking filter, but the embodiments are not limited thereto. Thefilter 470 may be disposed above the image sensor 300. The filter 470may be disposed inside the sensor base 460.

The sensor base 460 may be disposed below the middle base 450, and maybe attached to the main board 480. The sensor base 460 may surround theimage sensor 300, and may protect the image sensor 300 from foreignsubstances or external impacts.

The main board 480 may be disposed below the sensor base 460, the sensorbase 460 may be mounted on the main board 480 so as to be spaced apartfrom the circuit elements 481, and the holder 430 in which the middlebase 450, the second lens unit 440, the liquid lens module 130, and thefirst lens unit 420 are disposed may be disposed above the sensor base460.

Hereinafter, a comparison between a comparative example and the cameramodule according to the embodiment will be made. The comparative exampleset forth herein is merely illustrative in order to help understand theeffects of the camera module according to the embodiment, and is not arelated or conventional art.

FIGS. 15(a) and (b) are partial plan views of a camera module accordingto the comparative example.

The camera module according to the comparative example shown in FIGS.15(a) and (b) includes a liquid lens 10, a thermistor 20, and a heater30.

The liquid lens 10 may include first electrodes E1, which are individualelectrodes, and a second electrode E2, which is a common electrode.Here, the first electrodes E1 and the second electrode E2 respectivelycorrespond to the first electrodes E1 and the second electrode E2according to the above-described embodiment. The thermistor 20 is usedto sense the temperature of the liquid lens 10. In addition, the heater30 serves to heat the liquid lens 10.

As shown in FIG. 15(a), in the liquid lens 10 according to thecomparative example, the thermistor 20 is disposed on the surface onwhich the second electrode E2 is disposed (e.g. corresponding to thesecond surface SF2 shown in FIG. 3) so as to be spaced apart from thesecond electrode E2. However, when the thermistor 20 is disposed on thesecond surface SF2, on which the common electrode E2 is disposed, thethermistor 20 may affect the common electrode E2, leading to anoperational problem. In contrast, in the case of the camera moduleaccording to the embodiment, the resistor 120A or 120B, which serves asthe thermistor 20 or the heater 30, is disposed on the first surfaceSF1, on which the individual electrodes E1 are disposed, rather thanbeing disposed on the second surface SF2, on which the common electrodeE2 is disposed, whereby influence on the common electrode E2, which is areference electrode, may be prevented, and thus operational stabilitymay be secured.

In addition, in the case of the comparative example, the thermistor 20is disposed on the surface on which the second electrode E2 shown inFIG. 15(a) is disposed (i.e. corresponding to SF2 of the embodiment),rather than being disposed on the first surface (i.e. corresponding toSF1 of the embodiment), on which the first electrodes E1 are disposed.However, when the thermistor 20 is disposed on the second surface SF2,which is has a smaller area than the first surface SF1, the area inwhich to dispose the thermistor 20 is small. In order to increase thisarea, it is required to increase the overall size of the liquid lens 10.If the size of the liquid lens 10 is increased, the size of the lensassembly accommodating the liquid lens 10 may be increased, which mayresult in an increase in the overall size of the camera module.Accordingly, it is difficult to apply the comparative example to acamera module having a reduced bezel or no bezel. In contrast, in thecase of the camera module 1000 or 1000A according to the embodiment, theresistor 120A or 120B, which performs the same function as thethermistor 20 of the comparative example, is disposed on the firstsurface SF1, which is wider than the second surface SF2 of the firstplate P1 in the liquid lens 110A. Thus, the resistor 120A or 120B, whichserves as the thermistor 20, can be disposed in a larger area on thefirst surface SF1 compared to the comparative example, obviating theneed to increase the overall size of the liquid lens 110 or 110A.Accordingly, in the camera module according to the embodiment, it ispossible to easily reduce the size of a bezel or eliminate a bezel. Inparticular, considering that the temperature of the liquid lens 110 ismore accurately sensed when the size of the thermistor 20 is larger, itis apparent that the embodiment is capable of more accurately sensingthe temperature of the liquid lens 110 than the comparative examplebecause the resistor 120 (120A and 120 b) of the embodiment, whichserves as the thermistor 20, can be formed over a larger area than thethermistor 20 of the comparative example.

In addition, in the case of the camera module according to thecomparative example, the heater 30 is disposed on a surface on which thefirst electrodes E1 are disposed, as shown in FIG. 15(b), and thethermistor 20 is disposed on a surface on which the second electrode E2is disposed, as shown in FIG. 15(a). In contrast, in the case of thecamera module according to the embodiment, since the resistor 120A or120B, which is capable of serving both as the thermistor 20 and as theheater 30 of the comparative example, is disposed on the first surfaceSF1 of the first plate P1, utilization of space is improved.

Although only a limited number of embodiments have been described above,various other embodiments are possible. The technical contents of theabove-described embodiments may be combined into various forms as longas they are not incompatible with one another, and thus may beimplemented in new embodiments.

An optical device may be implemented using a camera module 1000 or 1000Aincluding the liquid lens according to the embodiments described above.Here, the optical device may include a device that may process oranalyze optical signals. Examples of the optical device may includecamera/video devices, telescopic devices, microscopic devices, aninterferometer, a photometer, a polarimeter, a spectrometer, areflectometer, an auto-collimator, and a lens-meter, and the embodimentsmay be applied to optical devices that may include a lens assembly.

In addition, the optical device may be implemented in a portable devicesuch as, for example, a smartphone, a laptop computer, and a tabletcomputer. Such an optical device may include the camera module 1000 or1000A, a display unit (not shown) configured to output an image, abattery (not shown) configured to supply power to the camera module 1000or 1000A, and a body housing in which the camera module 1000 or 1000A,the display unit, and the battery are mounted. The optical device mayfurther include a communication module, which may communicate with otherdevices, and a memory, which may store data. The communication moduleand the memory may also be mounted in the body housing.

It will be apparent to those skilled in the art that various changes inform and details may be made without departing from the spirit andessential characteristics of the disclosure set forth herein.Accordingly, the above detailed description is not intended to beconstrued to limit the disclosure in all aspects and to be considered byway of example. The scope of the disclosure should be determined byreasonable interpretation of the appended claims and all equivalentmodifications made without departing from the disclosure should beincluded in the following claims.

MODE FOR INVENTION

Various embodiments have been described in the best mode for carryingout the disclosure.

INDUSTRIAL APPLICABILITY

A camera module including a liquid lens and a control method thereofaccording to embodiments may be used in camera/video devices, telescopicdevices, microscopic devices, an interferometer, a photometer, apolarimeter, a spectrometer, a reflectometer, an auto-collimator, alens-meter, a smartphone, a laptop computer, a tablet computer, etc.

1. A camera module, comprising: a liquid lens comprising a first plateand an individual electrode disposed on a first surface of the firstplate; a resistor disposed on the first surface of the first plate so asto be spaced apart from the individual electrode; and a temperaturesensor connected to the resistor and configured to sense a temperatureof the liquid lens and a heating controller connected to the resistorand configured to control a temperature of the liquid lens.
 2. Thecamera module according to claim 1, wherein the temperature sensorcomprises a sensing driver configured to supply a sensing signal to oneend of the resistor, and wherein the heating controller comprises aheating driver configured to supply a heating signal to the one end ofthe resistor.
 3. The camera module according to claim 2, comprising: afirst switch disposed between the resistor and the sensing driver; asecond switch disposed between the resistor and the heating driver; anda switch controller configured to control the first and second switches.4. The camera module according to claim 2, wherein the resistorcomprises an opposite end connected to a reference potential.
 5. Thecamera module according to claim 3, comprising: a connection substrateconnected to the individual electrode and the resistor, wherein theresistor comprises first and second resistors, the first and secondresistors being disposed so as to face each other, with a center of theliquid lens interposed therebetween.
 6. The camera module according toclaim 5, wherein the temperature sensor is connected to one end of thesecond resistor via one end of the first resistor and an opposite end ofthe first resistor.
 7. The camera module according to claim 6, whereinthe heating controller is connected to the one end of the first resistorand the one end of the second resistor.
 8. The camera module accordingto claim 7, wherein the opposite end of the first resistor is connectedto a reference potential, and wherein the camera module comprises: athird switch disposed between the opposite end of the first resistor andthe reference potential; and a fourth switch disposed between theopposite end of the first resistor and the one end of the secondresistor. 9-10. (canceled)
 11. The camera module according to claim 5,wherein one end and an opposite end of the first resistor are disposedin a first edge area of the liquid lens, and wherein one end and anopposite end of the second resistor are disposed in a second edge areaof the liquid lens, the second edge area being an area that is oppositethe first edge area.
 12. The camera module according to claim 11,wherein the liquid lens comprises a second plate disposed on the firstsurface of the first plate.
 13. The camera module according to claim 12,wherein the first and second resistors are disposed between the firstsurface of the first plate and the second plate.
 14. The camera moduleaccording to claim 12, wherein the second plate comprises a plurality ofrecesses exposing the one end and the opposite end of each of the firstand second resistors, and wherein the connection substrate comprises aplurality of protruding portions protruding toward the liquid lens to beconnected to the one end and the opposite end of each of the first andsecond resistors exposed at the plurality of recesses.
 15. The cameramodule according to claim 14, wherein the plurality of protrudingportions protrudes from inner edge surfaces between inner corners of theconnection substrate.
 16. The camera module according to claim 5,wherein the first resistor and the second resistor face each other in afirst direction, wherein the first direction is perpendicular to asecond direction of an optical axis direction, wherein a third directionis perpendicular to each of the first and second directions, and whereinthe first resistor and the second resistor have planar shapes, which aresymmetric to each other with respect to a surface, which is parallel toeach of the second direction and the third direction and passes througha center of the liquid lens.
 17. The camera module according to claim 1,wherein the first plate comprises a second surface formed opposite thefirst surface, and wherein an area of the first surface is larger thanan area of the second surface.
 18. The camera module according to claim17, wherein the liquid lens comprises a first liquid and a second liquidaccommodated in a cavity of the first plate, wherein the first plateincludes a first opening and a second opening, the first and secondopenings defining the cavity, wherein the first opening has a smallerarea than the second opening, and wherein the first surface is a surfacearound the first opening and the second surface is a surface around thesecond opening.
 19. A camera module, comprising: a liquid lens, theliquid lens comprising: a first plate; a first electrode disposed on afirst surface of the first plate; and a second electrode disposed on asecond surface formed opposite the first surface, a resistor disposedwith being space apart from the first electrode, on the first surface,which is a wider than the second surface of the first plate; atemperature sensor connected to the resistor and configured to sense atemperature of the liquid lens; and a heating controller connected tothe resistor and configured to control a temperature of the liquid lens.20. The camera module according to claim 19, wherein the first electrodeincludes a plurality of individual electrodes, and wherein the secondelectrode includes a common electrode.
 21. A control method of thecamera module described in claim 1, comprising: sensing a temperature ofthe liquid lens; detecting a difference between the sensed temperatureand a set target temperature of the liquid lens; and applying power tothe resistor when there is a difference between the sensed temperatureand the set target temperature of the liquid lens.
 22. The controlmethod of the camera module described in claim 21, comprising:maintaining a current state when there is no difference between thesensed temperature and the set target temperature of the liquid lens.